Paint spraying machine



Feb. 25, 1947.

R. L. GRIFFIN ET AL PAINT SPRAYING MACHINE 5 Sheets-Sheet 1 Filed May 10 1943 Feb. 25, 1947.

R. L. GRIFFIN ETAL PAINT SPRAY ING MACHINE Filed May 10 1943 3 Sheets-Sheet 2 Patented Feb. 25, 1947 PAINT srmuzmc MACHINE Roger L. Griffin, Marblehead, and Norman Y.

Moore, Danvcrs,'Mass., assignors to A. 0. Lawrence Leather Company, Peabody, Mass., a corporation of Maine Application May 10, 1943, Serial No. 486,308

13 Claims. 1

The present invention relates to conveyors and more particularly to conveyors adapted for advancing articles or material past spraying devices for applying paint or analogous substances.

As spraying devices are commonly used at the present time, it is impossible to confine the spray to the work presented bythe conveyor. Thus a substantial amountof spray material is necessarily applied to more or less of the conveying surface'beyond the margins of the articles or work. As a result not only may the operation of the conveyor be interfered with by the presence or accumulation thereon of the spray material, but this material may be offset or transferred from the surface of the conveyor to those portions or the surfaces of the work whichcome. in contact with the fconveyor. With certain tion of these devices, the skins are raised and classes of work this is very objectionable as, for

example, in the case of woolskins or sheepskins where a stain is applied to the flesh side of the leather as the skins are being conveyed with the wool face resting upon the conveyor. Any stain o discoloration on the light colored wool great 1y impairs its marketability and value,

It is the object of the present invention to improve the construction and operation of such conveyors by insuring the complete removal from the surface of the conveyorof this waste spray material so that all likelihood or danger of its being later transferred'to the work will be eliminated. p A

With this object in view, the invention consists in the provision of means for cleaning the work engaging surface of the conveyor after it has passed beyond the range or zone of operation of the spraying devices, the work being temporarily raised from the conveyo at such time so that the entire width of the conveyor may be subjected to the cleaning operation, after which the work is returned to the conveyor for the completion of its movement on the same.

In the specific form of the present. inven-' tion illustrated in the accompanying drawings, the conveyor consists of a seriesof parallel, laterally spaced, endless bands, continuously driven to advance the work, such aswoolskins, past the. spraying devices which spray the stain to the flesh side of the skins as they rest withthe wool maintained above the surface of the conveyor by an air blast-from beneath, a supplementary support being provided to prevent any possibility of the skins returning to the conveyor until it had passed'beyondthe zone of operation of these devices. vThis zone of operationis relatively short so that only a small Portion of the length of the skin' is raised at one time, the feed of the work being continued through contact of the other portions with the conveyor.

' After the skin has been returned to the conveyor it continues its movement thereon for a suilicientduration of time to permit the stain to become sufiiciently set'so that the skin may be handled safely without danger of damage by the transfer of the stainmaterial from the flesh side of-one skin to the wool side of another when th 'skins are laid one upon another.

side upon the conveyor bands. Shortly beyond the range of the spray nozzles the flat steel con- \In the accompanying drawings" which'illu'strate a conveyor of theabove described construc- 7 tion and mode of operation, Fig. l-is a top plan view and Fig. 2 a side elevation oithe conveyor proper showing in somewhat diagrammatic manner the endlesswork supporting bands, with the end reels and guide rolls for the bands; Fig. 3 is a side elevation, on anjenlarged scale; showingthe reel at the discharge endof the con veyor with its guide rolls for .the bands, the guard above the reel, and the scraper for removing any foreign material from the 'surfaceof the reel; Fig. 4 shows, in end elevation, a portion of the discharge end of the conveyor on a; still larger scale, looking toward the right of Fig. 3'; Figs. 5 and 6 are detailsof the guard fo the conveyor bands, showing its construction and method of mounting; Fig. 7 is a transverse, vertical view taken on'lin l-'l of Figs. 1 and 2, and Fig. 8 is a top planview, on anenlarged scale, of a portion of vthe pneumatic means for raising the skins from the bands and passing them over the' devices for cleaning the bands 'Fig. 9 is a longitudinal,

vertical sectional view of such means and devices on the line 9-9 of Fig. 10; Fig. 10 is a 3 partially in section, showing the construction and arrangement of the water tank with its stripping. devices; Fig. ll shows on a still larger scale one of the individual dry strippers for the bands;

and Fig. 12 is a perspective view .of'one of the 7 strippers encircling its conveyor band. 7

The conveyor proper, as shown in Figs. 1 and 2, comprises a series of horizontally disposed, parallel traveling conveyor bands ll laterally spaced fromone another. These bands are preferably formed from strips of thin flat steel with the ends of such strips joined or united in any suitable manner to form an endless band.

The bands are supported at each end of the conveyor upon smooth faced reels l3 and I5 rotatably mounted on the frame I! of the machine. Reel I3 at the discharge and of the'conveyor is arranged to be driven from the motor 19 or other suitable source of power.

In order to maintain the conveyor bands in proper spaced relation and guide them onto and from the supporting reels, the guide rolls 2! and 23 are provided for the upper leg of the bands and the rolls 25 and 2! for the lower leg. .All

four guide rolls are formed with annular grooves in their faces, each of a. width anddepthto receivea conveyor band and spaced apart the de; sired distance. These rolls are freely rotatable in suitable bearings such as 29, carriedby the :frame. ll of the machine. The guide roll 2| is positioned close to the reel l3 at the discharge end of the conveyor, while the guideroll- 23 is spaced fromthe reel [Eat the receiving end of the conveyor to permit the placing of aework table 31 between said reel and. its guide roll and immediately beneath the conveyor bands.

To .avoid the possibility of the operators fingers being caught beneath the band and the reel I3 at the discharge end of the conveyor, a guard has been provided, shown in Figs. 356, which con;- sists of anarrow metal plate v33, extending trans versely across the conveyor bands ,andfthe' end reel 53 directly above the point of contact .or engagement of the bands with the surface of the reel. This plateis formed .with thedownturned flange and is provided with the notches 3] to receive the bands H. The guard issupported by the bracket 39, see Fig. .5, having the reversely the conveyor.

bent depending portions' dl to receive the flange 35 of the guard with tight frictionalengagement,

and is itself clampedfi x'edly imposition on the angle piece 43.

In order to remove any adherent foreignma.

7 19%, as Patent No..2,397,482, which is being in- 4 i H and the fact that ordinarily they will be spaced from one another along the conveyor, various portions of the top surfaces of the conveyor bands are exposed to the spray material being discharged from the nozzles, and as a result such exposed, parts receive a coating upon their upper or work supporting faces.

.The present invention is concerned primarily with the removal of this waste spray material from the bands before it has had time to set or an opportunity to be transferred to the wool face of the skin Briefly, such removal is accomplishedby cleaningpdevices including the application of a suitable cleaning liquid, which devices are positioned just beyond the zone of final operation offthe spray nozzles in the direction of travel of In connection with these cleaningdevices are means for lifting and supporting the were above the conveyor bands to permit said bands to be operated upon by such devices,

after which the work is returned to the conveyor to be carried to the discharge end thereof.

'The raisingmeans illustrated in the drawings are; the pneumatic type wherein jets of air-are discharged from beneath the conveyor bands upwardly between the same with sufficient ,forceto raise that portion of theskin immediately above. These pneumaticmeans are positioned adjacent the cleaningdevi'ces for the bands so that the skin will beheld raised from the bands as the latter are presented for cleaning.

To insure that the skinwill be maintained above the bandsuntil'ithas passed the cleaning devices, ,a fixed supporting plate has beenprovided which extends transversely across the conv'eyor bands and lengthwise of the same from a point adjacent thepneurnatic means for a sufilcient distance toward thedischarge end so that the skin may not fall upon the conveyorbands' until it is clear of the cleaning devices.

lhe pneumatic Work raising means, .as shown in Figs. 7, 8 and 9, comprise the transverse air pipe extending transversely across theconveyor immediately below the bands II. The upper surface of the pipe is provided with a row of airorifices til, each of which is positioned midway between adjacent bands, as shown in Fig. 8.. Air igsupplied to the pipe 55 by the rotary blower 59 driven fromany suitable source. of power through the belt'pulley 6! upon the fan rotor shaft during the operation of the conveyor. The

blower, is" continuously operated to supply air to I the-,ipip'e 55 from which it escapes upwardly through the orifice El atxsnfficiently high velocity to raise from the conveyorbands that portion of the skin immediately above the pipe.

By the time any particular portion of the skin has moved beyond the effective zone of the air dicated diagrammatically in Fig. VI of the drawingsby the dotted arcs 5! which indicate'jthe path of,.moveme'nt of the rotating spraying noz-" zles. ;As apparent from Fig. 1, each nozzle in a iullrotation passes twice over the conveyonand during these times the nozzle .is in ,operation,'but is cutoff and inoperative during those portions of its movement when it is beyond. the margins of the conveyor. I

Because of the irregular shape'of the woolskins,

blast, it has been carried over the adjacent por- Q tionof the supporting p1ate63,-which isconvexly curved on its upper surface, andextends transversely across the conveyor bands and longitudinally thereof a sufiicient' distance toinsure the j 'skinsclearing the cleaning devices. ,If the air blast .is not-heavy enough tosupport the skin for the entiredistance acrossthecleaningYdevices,.as it usually will do, the skin falls upon the plateand continuesto be advanced through contact of its'oth'er portions with the traveling bands,

being carried along the top surface of the plate andfinally returning tojtheconveyor band beyond the ,cleaning devices.

iair blast andsupported by the plate thdclean ing "devices operate sp il the conveyor bands.

p yin .the time. that the ,skin israised .by the The first of the cleaning devices is a dry stripper, shown in enlarged view in Fig. 11, and comprising a thin steel blade 65 provided with an L- shaped slot El and having at its lower end the weight 89. One of these dry strippers is hung upon each conveyor band H, the horizontal portion of the L-slot permitting the stripper to be applied to the band from the side. The vertical portion of the slot is of a width giving just suflicient clearance for the free passage of the band therethrough, the sides of the slot thus removing any accumulation of material from the side edges of the band while the metal of the stripper at the top of the slot scrapes off the major part of any accumulation from the spra nozzles or from the work;

Adjacent the dry stripper in the direction of the feed is a trough or tank It extending trans versely of the conveyor bands, with the major portion of the tank positioned beneath the bands,

and the front wall 73 and the rear wall 15 ex-' tending above the same. These extended portions of the walls are slotted as shown at 11 and 18 in Fig. 10, to receive the conveyor bands II,

The trough or tank H is supplied with water or other cleaning liquid to a, level well above the bands so that the latter will pass through the liquid. To prevent the escape of liquid through the slots TI and l8, packing means are provided, such as washers 19 and 8!? split inwardly on a radius as at 8|, and mounted in a split metallic ring 83 (see Fig, 12). These washers can he slipped onto the bands from one side or edge of the same and will press against the bands suificiently to act as a packing to prevent leakage of the liquid from the tank. These washers are supported by the bands themselves, and are drawn against the walls of the tank by the movement of the bands with suflicient pressure to maintain close contact with the walls. of the bands and prevent the escape of liquid from the tank. One of these washers, indicated at 19, is positioned on each band II on the outside face of thewall l3 where the band enters the tank through its slot "H, and the other washer 80 is held against the inside face of the wall 15 as the band leaves the tank through slot 18. These washers also help to clean the bands as they wipe top, bottom, and both edges of the same, the rings 33 squeezin the washers tight around the bands and closing the slots 8| therein. The washers may be of any suitable material, but preferably are formed of neoprene, as this is unaffected by oils and it is desirable to apply very small amounts of oil to the work contacting surface of the band in the manner hereinafter described.

To seal the slots El and 18 above the washers- For the purposeofremoving any of the water or other cleaning liquid which may be uponthe bands after they have passed the packing washers 80 on leaving the tank, a liquid stripper has, been provided in the form of one of these washers with split ring mounting 85 suspended upon the bands and held from movement therewith by the abutment 86 slotted downwardly from its top edge.

This washer efiectively wipes offv any liquid or moisture from the bands, together with any small amount of spray material which may have been 1 carried through the outlet washer 80. V

- material 9i, extending upwardly from an oil container 93 and bearing against the work engaging face of the band's. Only a very slight amount of oil is applied in this manner, just suflicient to give a very slight coating to the bands which will not only facilitate the removal of any waste spray material from the surface of the bands, but will also provide lubricant for the bands where they.

, are drawn through the strippers and washers.

- porting plate.

In the operation of the conveyor the skins are laid out by the operator over the table 3| with the fleece side down. After they are properly extended they are pushed by the operator slowly in the direction of the feed until they are picked. up byithe traveling bands and the rotating spacing roll 23 and. carried forward to the spraying devices. A second skin is then placed on the table and the operation repeated, the skins being spaced only a few inches apart so as to avoid so far as possible the waste of spray material between adjacent skins.

Asthe skin comes within the first path or zone of operation of the spray nozzles they re- Almost immediately thereafter the advancing edge of the skin is carried over the air jets and is lifted thereby, and as the skin continues to ad- Vance, the raised end portion of the skin passes over the supporting plate 63, returning to the bands after passing the cleaning devices. If the air is discharged in sufficient volume and at sufiiciently high velocity, the raised portion of the skin will continue to float and it may pass over thecleaning devices without contacting the sup- With lesser volumes and pressures the skin will fall upon the plate at various distances from the receiving edge, according to such volumes and pressures. Eventually the entire skin will be returned to the conveyor bands and will be carried to the discharge end of the conveyor where it will be removed by the operator.

Although a portion of the skin is out of contact with the bands as such portion passes over the cleaning devices, nevertheless its forward feeding movement continues through the contact of the leading or the following portions of the skin, or both, with the conveyor bands, as shown in'Fig. 9, the skin being indicated at 95. After the skin has been raised from the eon-. veyor bands, the latter'oontinue their forward movement, passing first through the dry stripper 65, then passing the washer l9, through the wall .l3-of the tank, andacross the samebeneath the surface of the water or other cleaning liquid; thence through the washer 86. through the slotted wall 15, and finally through the water stripper, and slotted abutment 86, after which it receives again the skin.

. 'In' this passage through the strippers, washers,

ass-6,622

and cleaning liquid any waste spray material which may have reached the bands between adjacent skins and beyond the outer edges of the same, is removed while still soft and before it has had an opportunity to set. Thus the bands are kept clean and the soiling or damaging of the light colored wool is effectively prevented.

While the present invention has been shown and described in one form of mechanism, it is to be understood that it is not necessarily limited thereto but may be embodied in many other different forms and arrangements, and the specific construction of the various portions of the apparatus may be varied without departing from the invention as defined in the appended claims.

Having thus described the invention, what is claimed is:

1. A conveyor having, in combination, movable means for supporting and advancing the work, driving mechanism for said means, devices for momentarily raising the work from said means and thereafter returning it thereto, and supplementary instrumentalities operating beneath the.

momentarily raised work to clean the supporting surfaces of the conveying means. 1 2. A conveyor having, in combination, a plurality of laterally spaced, endless, traveling bands to support and convey the work, supporting and driving mechanism for the bands, means positioned intermediate the ends of the conveyor for momentarily raising the work above the bands as it is carried past on the conveyor, and stripping devices through which the bands are passed for cleaning the bands beneath the raised por tion of the work. 3. A conveyor having, in combination, a plurality of laterally spaced, endless, traveling bands to support and convey the work, supporting and driving mechanism for the bands, means for momentarily raising the work above the bands as it is carried past on the conveyor, and devices for applying cleaning fluid to the bands and for removing the fluid and foreign material from the bands, said devices operating beneath theraised work. 4. A conveyor having, in combination, a plurality of laterally spaced, endless, traveling bands to support and convey the work, supporting and driving mechanism for the bands, means positioned intermediate the ends. of the conveyor and'beneath the bands for momentarily raising the work above the bands as it is carried past on the conveyor, a tank for cleaning liquid positioned beneath the bands and adjacent the work raising means, guiding devices for guiding the bands beneath the surface of the cleaning liquid, and strippers for-removing the liquid and foreign material from the bands. 5. A conveyor having, in combination, a plurality of laterally spaced, endless, traveling bands to support and convey the work, supporting and driving mechanism for the bands, means positioned intermediate the ends of the conveyor for momentarily raising the work above the bands 7 ralityof laterally spaced, endless, traveling'bands to support and convey the work, supporting and driving mechanism for the bands, means for momentarilyraising'the work iromthe bands, scra ing devices for scraping torei'gnfmaterial"from the bands, said; devices eachcomprising. a weighted member having a scraping blade, said mem her being hung upon a band with the blade in contact with the work engaging face of the band and held from movement with the band, and

being positioned to operate beneath the raised portion of the Work.

7. A conveyor having, in combination, a plurality of laterally spaced, endless, traveling bands to support and convey the work, supporting anddriving mechanism for the bands, means for momentarily raising the Work from the bands, and devices positioned beneath the raised portion of the, work for cleaning the bands, said devices each comprising a disk of compressible material slotted radially to receive a band with a tight sliding fit and held from movement with the band.

8. A conveyor having, in combination, a plurality of laterally spaced,endless, traveling bands to support and convey the work, supporting and driving mechanism for the bands, means positioned intermediate the ends of the conveyor 'for momentarily raising the work above the bands as it is carried past on the conveyor, and a support for supporting the raised portion of the work to permit it to travel momentarily out of contact with the bands and thereafter to rest upon them again.

9. A conveyor having, in combination, a plurality of laterally spaced, endless, traveling bands to support and convey the work, supporting and driving mechanism for the bands, means positioned intermediate the ends of the conveyor for momentarily raising the work above the bands as it is carried past on the conveyor, and a,sta-

tionary work support extending transversely across the bands above the same to receive the portion of the work raised from the bands by said means and to support the same momentarily and to deliver such portion onto the bands, all while another portion of the work remains upon the bands to advance the portion out of contact with the bands. 7

10. The combination with spraying devices of a conveyor for supporting the work and conveying it through the field of operation of said devices, and means adjacent said field of operation for momentarily raising the sprayed work from the conveyor and cleaning the conveyor adjacent the raised work.

11. A conveyor having, in combination, a plurality of laterally spaced, endless, traveling bands to support and convey the work, supporting and driving mechanism for the bands, means positioned intermediate the ends of the conveyor and beneath the bands for momentarily raising the work above the bands as it is carried past on the conveyor, a tank for cleaning liquid for cleancent the work raising means, and a work supporting plate positioned above the top of the tank to support the raised portion of the work as it is passing over the tank.

12. The combination with spraying devices of a conveyor for supporting the work and conveying it beneath said devices,- means beneath the conveyor and adjacent the spraying devices for momentarily raising the sprayed work from the conveyor, and supplementary devices adjacent said means for cleaning the surfaces 'of the conveyor exposed to the action of the spraying de vices.

13. Aconvey'o'r having, in combination, movable means having a transversely discontinuous surfacefor supporting and advancing the work, driving mechanism forsaid means, pneumatic de.

ing the bands, the tank being positioned adja- 9 vices for directing a blast of air through the discontinuous surface of the movable means for momentarily raising the work from said means and thereafter returning it thereto, and supplementary instrumentalities operating beneath the momentarily raised work to clean the supporting surface of said movable means.

ROGER L. GRIFFIN.

NORMAN Y. MOORE.

REFERENCE S CITED The following references are of record in the file of this patent:

Number 10 UNITED STATESPATE'NTS Name Date Lichtenstein et a1. Sept. 29, 1914 Peters et a1 May 22, 1917 Post et a1 Oct. 27, 1931 Zadernach June 2, 1942 Jones et a1 May 3, 1927 Sullivan Apr. 30, 1929 Sejnoha et a1 May 26, 1903 Schwartz Mar. 7, 1911 Sargent Jan. 25, 1916 

